Carbon and oxygen in HII regions of the Magellanic Clouds: abundance discrepancy and chemical evolution

We present C and O abundances in the Magellanic Clouds derived from deep spectra of HII regions. The data have been taken with the Ultraviolet-Visual Echelle Spectrograph at the 8.2-m VLT. The sample comprises 5 HII regions in the Large Magellanic Cloud (LMC) and 4 in the Small Magellanic Cloud (SMC). We measure pure recombination lines (RLs) of CII and OII in all the objects, permitting to derive the abundance discrepancy factors (ADFs) for O^2+, as well as their O/H, C/H and C/O ratios. We compare the ADFs with those of other HII regions in different galaxies. The results suggest a possible metallicity dependence of the ADF for the low-metallicity objects, but more uncertain for high-metallicity objects. We compare nebular and B-type stellar abundances and we find that the stellar abundances agree better with the nebular ones derived from collisionally excited lines (CELs). Comparing these results with other galaxies we observe that stellar abundances seem to agree better with the nebular ones derived from CELs in low-metallicity environments and from RLs in high-metallicity environments. The C/H, O/H and C/O ratios show almost flat radial gradients, in contrast with the spiral galaxies where such gradients are negative. We explore the chemical evolution analysing C/O vs. O/H and comparing with the results of HII regions in other galaxies. The LMC seems to show a similar chemical evolution to the external zones of small spiral galaxies and the SMC behaves as a typical star-forming dwarf galaxy.Comment: Accepted for publication in MNRAS, 17 pages, 11 figures, 8 table

Heterogeneous combustion processes under microgravity conditions

An experimental programme on flame spreading over the surface of PMMA (plexiglass) samples has been conducted under microgravity conditions in the NASA KC-135 aircraft laboratory. A few experiments (three) were conducted in 1986 under the preceding contract no. 6284/85/F/FL, but the largest part of the experimental programme has been carried out under the present contract in two parabolic flights campaigns. A total of 36 experiments were performed, most of them successful. From the results of these experiments the flame-spreading velocities over PMMA samples have been obtained, as well as their laws of variation with pressure and mixture composition. Both cylindrical (axial symmetry) and flat (bidimensional symmetry) samples have been investigated

Diploic venous system: radiological-anatomical correlation

El sistema venoso diploico se encuentra ubicado entre la tabla externa e interna de los huesos planos de la calvaria craneana. A pesar de tener más de 200 años de descripto, es escasa la referencia en la literatura anatómica y antropológica. Merece destacarse que estos canales pueden ser confundidos con trazos fracturarios en la evaluación radiológica del traumatismo encéfalocraneano. En este trabajo nos proponemos describir las principales variantes anatómicas del sistema venoso diploico y determinar su distribución topográfica. Para ello realizamos un estudio descriptivo de corte transversal con una muestra de cráneos humanos (n=108), los cuales fueron transiluminados mediante introducción de fuente lumínica por el foramen magno. También se analizaron placas radiográficas de cráneo de perfil (n=60), discriminando topográficamente la ubicación de dichas venas. Se encontraron 5 patrones de distribución diferentes y un sexto como patrón indeterminado. Se determinó el porcentaje de hallazgo de venas diploicas según regiones. Lo obtenido se contrastó con la literatura clásica, llegando a la conclusión de la importancia que adquiere el conocimiento de estos patrones ante el diagnóstico diferencial de un trazo radiolúcido en una placa radiográfica de cráneo ante un traumatismo encéfalocraneano.The diploic venous system is located between the outer and inner table of the flat bones of the skull calvaria. Despite the fact that it has been described over 200 years ago, there is little reference on the matter in anatomical and anthropological literature. It is remarkable that these channels can be confused with fractures in the radiologic evaluation of head trauma. This study describes the main anatomical variants of the diploic venous system and illustrates their topographic distribution. In order to achieve this goal, a cross sectional study was conducted utilizing a sample of human skulls (n=108), which were transilluminated by introducing a light source through the foramen magnum. In addition, lateral skull radiographs (n=64) were analyzed, as means of discriminating the topographical location of the veins. Hence, 5 different distribution patterns were discovered, as well as a sixth undetermined pattern. The probability of finding diploic veins in each region was determined, and the results were compared to the theoretical framework. As a conclusion, it can be said that the learning of these patterns and becoming familiarized with their anatomic variants is of significant importance when considering differential diagnosis of a radiolucent line on a skull which has undergone head trauma.Sociedad de Ciencias Morfológicas de La Plat

DESCRIPCIÓN DE LOS GENOTIPOS DE C. TRACHOMATIS EN EL HOSPITAL DE BASURTO-BILBAO

Se describen las características genotípicas de los aislamientos de C. trachomatis en una consulta de infecciones de transmisión sexual (ITS) en Bilbao para valorar la posible introducción de la cepa cwCT, variante aislada en Suecia, en la población diana del hospital de Basurto-Bilbao

Diploic venous system: radiological-anatomical correlation

El sistema venoso diploico se encuentra ubicado entre la tabla externa e interna de los huesos planos de la calvaria craneana. A pesar de tener más de 200 años de descripto, es escasa la referencia en la literatura anatómica y antropológica. Merece destacarse que estos canales pueden ser confundidos con trazos fracturarios en la evaluación radiológica del traumatismo encéfalocraneano. En este trabajo nos proponemos describir las principales variantes anatómicas del sistema venoso diploico y determinar su distribución topográfica. Para ello realizamos un estudio descriptivo de corte transversal con una muestra de cráneos humanos (n=108), los cuales fueron transiluminados mediante introducción de fuente lumínica por el foramen magno. También se analizaron placas radiográficas de cráneo de perfil (n=60), discriminando topográficamente la ubicación de dichas venas. Se encontraron 5 patrones de distribución diferentes y un sexto como patrón indeterminado. Se determinó el porcentaje de hallazgo de venas diploicas según regiones. Lo obtenido se contrastó con la literatura clásica, llegando a la conclusión de la importancia que adquiere el conocimiento de estos patrones ante el diagnóstico diferencial de un trazo radiolúcido en una placa radiográfica de cráneo ante un traumatismo encéfalocraneano.The diploic venous system is located between the outer and inner table of the flat bones of the skull calvaria. Despite the fact that it has been described over 200 years ago, there is little reference on the matter in anatomical and anthropological literature. It is remarkable that these channels can be confused with fractures in the radiologic evaluation of head trauma. This study describes the main anatomical variants of the diploic venous system and illustrates their topographic distribution. In order to achieve this goal, a cross sectional study was conducted utilizing a sample of human skulls (n=108), which were transilluminated by introducing a light source through the foramen magnum. In addition, lateral skull radiographs (n=64) were analyzed, as means of discriminating the topographical location of the veins. Hence, 5 different distribution patterns were discovered, as well as a sixth undetermined pattern. The probability of finding diploic veins in each region was determined, and the results were compared to the theoretical framework. As a conclusion, it can be said that the learning of these patterns and becoming familiarized with their anatomic variants is of significant importance when considering differential diagnosis of a radiolucent line on a skull which has undergone head trauma.Sociedad de Ciencias Morfológicas de La Plat

Phymatotrichopsis root rot and its biological control in the pecan tree in Mexico

In Mexico, phymatotrichopsis root rot is regarded as the most important disease in the pecan tree. Its causative agent is the fungus Phymatotrichopsis omnivora (Duggar) Hennebert, and the percentage of diseased trees ranges between 3 to more than 25% in a plantation. Symptoms vary from mild damages to the death of the infected tree. The roots invaded by the fungus die with the consequent reduction of the foliage. Chemical control is one of the most used methods to control this pathogenic fungus, but it is expensive and not very efficient, so it is necessary to try other methods such as antagonistic fungi, resistant varieties, plant extracts, among others that have been shown to have some effectiveness, and to design an integrated management program for the pest. For all the reasons stated, the objective of this review was to address the most current aspects of the disease and its biocontrol in Mexico

High resolution spectroscopy of the BCD galaxy Haro 15: II. Chemodynamics

We present a detailed study of the physical properties of the nebular material in four star-forming knots of the blue compact dwarf galaxy Haro 15. Using long-slit and echelle spectroscopy obtained at Las Campanas Observatory, we study the physical conditions (electron density and temperatures), ionic and total chemical abundances of several atoms, reddening and ionization structure, for the global flux and for the different kinematical components. The latter was derived by comparing the oxygen and sulphur ionic ratios to their corresponding observed emission line ratios (the $\eta$ and $\eta$' plots) in different regions of the galaxy. Applying the direct method or empirical relationships for abundance determination, we perform a comparative analysis between these regions. The similarities found in the ionization structure of the different kinematical components implies that the effective temperatures of the ionizing radiation fields are very similar in spite of some small differences in the ionization state of the different elements. Therefore the different gaseous kinematical components identified in each star forming knot are probably ionized by the same star cluster. However, the difference in the ionizing structure of the two knots with knot A showing a lower effective temperature than knot B, suggests a different evolutionary stage for them consistent with the presence of an older and more evolved stellar population in the first.Comment: 21 pages, 6 figures, 8 tables, accepted by MNRA

P67 195. Cirugía del tromboembolismo pulmonar masivo en el enfermo crítico

La extracción de los trombos pulmonares en el tromboembolismo pulmonar masivo antes de 1953 (operación de Trendelenburg) cosechó fracaso tras fracaso. Desde el advenimiento de la circulación extracorpórea (CEC) el porcentaje de éxito de esta operación mejoró notablemente, no habiendo dejado de aumentar hasta la actualidad, existiendo series que reflejan porcentajes de hasta el 94% de supervivencia inmediata, con 86 y 83% de supervivencia actuarial a 1 y 3años.Presentamos un caso de paciente varón de 35años sin enfermedad previa ni antecedentes familiares de enfermedad tromboembólica. Consulta por insuficiencia respiratoria, siendo diagnosticado por tomografía computarizada de tromboembolismo en AP izquierda, la cual ocluye. El ECO-Doppler de MMII descarta trombosis venosa profunda (TVP). Una nueva tomografía computarizada informa de persistencia de la obstrucción de AP izquierda y sus ramas, que parece haber aumentado. En ecocardiografía transtorácica (ETT) dilatación de cavidades derechas con función de ventrículo derecho (VD) normal y presión sistólica de la arteria pulmonar (PSAP) de 70 mmHg. Los estudios para investigar trombofilia fueron negativos.Tras unos días empeora su situación, produciéndose dos paradas cardiorrespiratorias, de las que es reanimado y tratado inmediatamente con TNK. La tomografía computarizada muestra la existencia de nuevo episodio de tromboembolismo pulmonar que afecta a la AP derecha gravemente.Es intervenido quirúrgicamente bajo CEC sin parada circulatoria, extrayéndose molde trombótico de tronco y ambas ramas de la AP. La evolución postoperatoria fue favorable. En tomografía computarizada de control se observan limpios el tronco y las ramas de la AP, con cierto compromiso en ramas subsegmentarias de la AP izquierda.Se muestran imágenes de la intervención y tomografía computarizada pre y posquirúrgicas

Functional Heterogeneity of Mouse and Human Brain OPCs: Relevance for Preclinical Studies in Multiple Sclerosis.

Besides giving rise to oligodendrocytes (the only myelin-forming cell in the Central Nervous System (CNS) in physiological conditions), Oligodendrocyte Precursor Cells (OPCs) are responsible for spontaneous remyelination after a demyelinating lesion. They are present along the mouse and human CNS, both during development and in adulthood, yet how OPC physiological behavior is modified throughout life is not fully understood. The activity of adult human OPCs is still particularly unexplored. Significantly, most of the molecules involved in OPC-mediated remyelination are also involved in their development, a phenomenon that may be clinically relevant. In the present article, we have compared the intrinsic properties of OPCs isolated from the cerebral cortex of neonatal, postnatal and adult mice, as well as those recovered from neurosurgical adult human cerebral cortex tissue. By analyzing intact OPCs for the first time with 1H High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (1H HR-MAS NMR) spectroscopy, we show that these cells behave distinctly and that they have different metabolic patterns in function for their stage of maturity. Moreover, their response to Fibroblast Growth Gactor-2 (FGF-2) and anosmin-1 (two molecules that have known effects on OPC biology during development and that are overexpressed in individuals with Multiple Sclerosis (MS)) differs in relation to their developmental stage and in the function of the species. Our data reveal that the behavior of adult human and mouse OPCs differs in a very dynamic way that should be very relevant when testing drugs and for the proper design of effective pharmacological and/or cell therapies for MS.post-print753 K